Remedial Strategies for the Minimization of Cogging torque in PMBDC Motor possessing Material Saturation

This paper investigates the various strategies for the minimization of cogging torque produced in a permanent magnet brushless DC (PMBDC) motor for a low speed, speed stability stringent spacecraft application with cold coil redundancy. The effect of the material saturation on cogging torque is analyzed using both FE software simulation and hardware simulation. Based on the simulation, suitable method has been derived for the minimization of the cogging torque for this particular application and the machine is realized. Test results shows that a decrease of 90% of the cogging component with 20% of alignment component in the developed torque pattern once saturation is removed.